Preheat the oven to 350°F.
In a large bowl, cream together ½ cup + 2 tablespoons of butter and 1 ½ cups of granulated sugar.
Add 3 eggs and 1 ½ tablespoons of vanilla bean paste, mixing until combined.
Mix in 1 cup of buttermilk until well blended.
In a separate bowl, sift together 2 ¼ cups of cake flour, ½ teaspoon of salt, 1 ½ teaspoons of baking powder, and ¼ teaspoon of baking soda.
Gradually add the dry ingredients to the wet ingredients, mixing until everything is combined.
Divide the batter evenly between three greased 6-inch cake pans.
Bake the cakes for 35-38 minutes, or until a toothpick comes out clean from the centers.
Let the cakes cool in their pans for 5 minutes, then transfer them to a cooling rack to cool completely.